Very little is known about Isabella Whitney. Living during the 16th Century, she was extremely unusual for several reasons. She was a writer (which was a limited option for women of the time), but she was also not of the upper class, but of the middle class. Therefore, her family did not have an excess of cash, and unmarried, Isabella even took the position as a servant to make money.
The fact that she was able to read and write speaks of an education of some kind, but not necessarily a formal education. While her brother Geoffrey was sent to school in Audlem (perhaps as part of the church there), this would not have been unusual for a boy. Later he would go on to Oxford and even another university, but he never earned a degree.
Women did not attend schools...even women of the aristocracy. They had tutors. As Isabella was of the middle class (a relatively new social class with the fall of feudalism), she would probably have been educated at home.
She came from a reformist family which allowed the daughters as well as sons access to a certain degree of humanist education.
She was not kept from an education, as many women would have been, but would probably have had a tutor or someone from the local church to tutor her—especially as they did not have a great deal of money.
Because little history of Isabella survives, it is difficult to be certain of much about her life beyond what she wrote in her poetry.